IBM RT PC 10 Hardware Maintenance And Service page 125

Step 2
1. Remove the boards from slots Band D, and record the type and slot
position.
2. Set the power switch on the system unit to On.
3. Wait two minutes, then answer the following question.
3-80 Service Manual
IS "23" DISPLAYED IN THE TWO-DIGIT DISPLAY?
YES Go to "Step 7" on page 3-85.
NO Continue on the next page.